Ab initio study of the structural, electronic and optical properties of NaTaO3

Eyi E. E., ÇABUK S.

PHILOSOPHICAL MAGAZINE, vol.90, no.21, pp.2965-2976, 2010 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 90 Issue: 21
  • Publication Date: 2010
  • Doi Number: 10.1080/14786431003752159
  • Journal Name: PHILOSOPHICAL MAGAZINE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.2965-2976
  • Keywords: NaTaO3, electronic band structure, optical properties, ab initio calculation, perovskite, 1ST-PRINCIPLES, FERROELECTRICITY, TEMPERATURE, KTAO3, GAS
  • Çukurova University Affiliated: Yes

Abstract

Ab initio calculations were performed of the structural, electronic and optical properties of the cubic ([image omitted], tetragonal ([image omitted], and orthorhombic ([image omitted]) phases of NaTaO3 using a plane-wave pseudopotential method within the density-functional theory. Results are presented for the structural properties, electronic band structure, density of states and imaginary and real parts of the frequency-dependent linear optical response. Cubic and tetragonal NaTaO3 both have an indirect band gap, at the R- and Z- points, respectively, whereas, orthorhombic NaTaO3 has a direct band gap at the - point. The optical properties of NaTaO3 were investigated by ab initio calculation under the scissor approximation. The real and imaginary parts of the dielectric function and, hence, the optical constants (such as absorption coefficient and the electron energy-loss spectrum) were calculated. This is the first quantitative theoretical prediction of optical properties, except for absorption of the orthorhombic phase, of the NaTaO3 compound.